The present disclosure relates to a toner transportation device that supplies toner to a developing unit, a toner case that contains toner, an image forming apparatus equipped with the toner transportation device and the toner case, and method of controlling the toner transportation device.
Today, in electrophotographic image forming apparatuses, toner is supplied from a developing unit to an electrostatic latent image formed on the surface of a photoconductor drum, or the like, to perform a developing process. Toner used in such a developing process is supplied to the developing unit from a toner case using a transportation unit while being agitated by an agitating unit.
In an image forming apparatus having such a structure, the toner case may be in an overload state immediately after the toner case is replaced or when an image forming operation has not been performed for a long time. Herein, an overload state of the toner case refers to a state wherein toner has become clumped in the toner case because of the weight of the toner or due to other causes. When the toner is supplied from the toner case to the developing unit in such a state, an excessive load torque is applied to a driving unit that drives the transportation unit and the agitating unit. As a result, there is a possibility of the driving unit being damaged.
In order to prevent such a situation from occurring, there are known image forming apparatuses that stop the driving unit, when it is detected that the toner case is in an overload state, and displays a warning notice that prompts a user, for example, to remove the toner container, shake the toner container well, and remount the toner container, or displays an error notice that prompts the user to contact a service engineer.
However, when the above-described warning notice is displayed, an operation to clear the overload state of the toner container will be performed by the user. This increases the amount of work performed by the user. When the error notice is displayed, the user cannot use the image forming apparatus until the toner container is replaced by a service engineer. This decreases convenience.